Object model in Visual Basic for Application (VBA)

Object-oriented environment

Concept	Example in Access
Object	A field in a table A form A control on a form A query
Properties	Form controls have: color and font Fields have: data type, size
Methods	Closing an application
Event	A form control gets focus (contain the cursor)

1. 2 types of objects

• collection object/class
• individual object

2. Each application has its object model

• Excel: Application à Workbooks à Worksheets à Range

• Word

• Access

• PowerPoint: Application à Presentation à Slides

3. Referring to objects

• Location of the object in its hierarchy using dot member selection operator: item to its right is a member of the item to its left

e.g., Application.Presentations

• Specific object can be referred to by its name enclosed in quotation marks or the object’s position number (or index) within the collection

e.g., Application.Presentations(“lecture6.ppt”).Slides(“slide3”) or Application.Presentations(1).Slides(3)

4. Referring to an object’s properties (characteristics) or methods (actions)

• Use the dot member selection operator to separate the object from its property/method

e.g., Application.Presentations.Count – returns the number of presentations currently open

e.g., Application.Presentations.Quit – instructs the application to close itself